Clear picture—blurry story?

Figure 1. The spiral galaxy NGC 4319 (centre) and quasar Markarian
205 (upper right). This reversed NASA image represents 1.8 arcminutes across and
is a composite of two shots, one taken in 1997 and another in 2002. Altogether 1.4
hours of HST observations were used to create the image. Note the bridge is faintly
visible.

In 2002, NASA published a picture from the Hubble Space Telescope (HST) of a famous
celestial duo in the constellation Draco—the spiral galaxy NGC 4319 and the quasar
Markarian 205 (Mrk 205).1 NASA’s
picture (Figure 1), published through the Space Telescope Science Institute, reveals
incredible detail in the celestial pair. But the accompanying press seems blurred.

The article asserts that ‘appearances can be deceiving’. This is because,
although the two objects appear to be neighbours, in reality, according to NASA,
they ‘don’t even live in the same city’. Blandly the article declares
that the duo is separated by time and space. According to NASA, NGC 4319 is 80 million
light-years from Earth and Mrk 205 is more than 14 times farther out, residing 1
billion light-years away. NASA explains that the apparent close alignment of Mrk
205 and NGC 4319 as ‘simply a matter of chance’.

The justification? Astronomers used two methods to determine the distances to these
objects. First, they measured how their light has been stretched in space due to
the universe’s expansion. Then they measured how much the ultraviolet light
from Mrk 205 dimmed as it passed through the interstellar gas of NGC 4319.1
Presto!

Thirty years of controversy ignored

Most people would not know the history behind this celestial ‘odd couple’.
Those who do know are dumfounded by the attitude in this article. This celestial
duo has been a source of contention for 30 years and is still controversial.2 But you would never learn that from
the NASA press release.

This celestial duo has been a source of contention for 30 years and is still controversial.

Halton Arp observed and reported some unusual features about this pair in 1971.
They appear very close in the sky but have vastly different redshifts (0.00453 for
the galaxy and 0.07085 for the quasar). If redshift is a reliable indicator of stellar
distance, then obviously their closeness must be just a fluke. Yet Arp reported
a visible connection between the two (Figure 2).3

This couple has prompted an extensive exchange in the astronomical literature. For
example, in 1983 Jack Sulentic published a definitive paper showing the reality
of the connection.4 Further papers
were published with Arp in 1987.5,6The duo is discussed in both of Arp’s books.7,8
They were observed by an amateur in the 1990s using the HST, and the connection
confirmed, but these observations were not published.9

After all this debate we now get this STScI press release (repeated in Sky and Telescope,10 and Astronomy11 magazines), which does not mention any of
the previous 30 years of serious observation, scientific debate, or controversy!

Figure 2. An isophote of the galaxy and the quasar (above) from
the 200 inch Palomar telescope (north is up, east is left). The luminous bridge
connecting the two objects is clearly visible, indicating they not only appear to
be neighbours, but are neighbours. This photo appears in Arp, Ref. 7.

Interpretations driven by cosmology?

The NASA commentary on the space image refers to dark and unusually misshapen dust
lanes in the galaxy’s inner region and claims they are evidence of a disturbance.
Of course they can’t attribute this disturbance to the quasar which appears
alongside the galaxy, in the image as large as life. That’s because, driven
by their ideological framework, they have already placed the quasar a billion light
years away. So, the disturbance must be due to some unseen cause, perhaps another
galaxy not visible in the photograph. These interpretations seem to be motivated
less by the observations of the billion-dollar HST, and more by a prior cosmological
commitment. It is hard to imagine that this is the best way for science to proceed.

It seems that some people would like to erase part of the history of astronomy.
Is this because the NGC-4319 observations are so problematical for current cosmological
thinking? The discussions in scientific journals over 30 years that have seriously
questioned the methods of measuring distance are ignored. Is this omission to protect
the current cosmological view from the need to compete with any contrary opinion?

A reviewer described some simple experiments using the HST
image available from the NASA Web site (Ref. 1), which demonstrate the existence
of the connection between NGC 4319 and Mrk 205. It should be possible for any interested
reader to repeat these experiments. When the story was published late in 2002 he
downloaded the NASA photograph for the wallpaper on his PC at work. A few days later
the lights in the office were switched off for testing, and by averted vision in
the relative darkness (a very familiar technique to variable-star observers) it
was quite easy to see the connection between the galaxy and the quasar. Later, one
of his colleagues passed the new NASA image through special image processing software
and readily produced a picture just like those produced in the past by Arp and Sulentic
(e.g. Refs 5 and 6), again confirming the connection! Return to text.